Microscopy and Taxonomy Quiz

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Questions and Answers

What does the symbol 'd' represent in the Abbé equation?

Distance between two resolvable points (correct)

Refractive index of the medium

Wavelength of light

Angle of the cone of light

Which aspect of microscopy is improved by Köhler illumination?

Depth of field and brightness

Color rendition and magnification

Field of view and working distance

Resolution and contrast (correct)

In the Abbé equation, what is represented by 'n'?

Refractive index of the medium (correct)

Wavelength of light

Distance from the objective lens to the specimen

Magnitude of light intensity

What function does the aperture iris diaphragm serve in Köhler illumination?

It controls the size of the cone of light Signup and view all the answers

What is the significance of numerical aperture (N.A) in microscopy?

It assesses the lens's ability to gather light. Signup and view all the answers

What is the correct order of the taxonomic hierarchy from broadest to narrowest?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species Signup and view all the answers

Which taxonomic rank represents a group of species with similar characteristics?

Genus Signup and view all the answers

Which of the following is NOT a category in the hierarchical taxonomic system?

Fungi Signup and view all the answers

What is meant by the term 'taxa' in the context of classification?

Groups of organisms within a specific taxonomic category Signup and view all the answers

Which hierarchical level is more general than 'Phylum'?

Kingdom Signup and view all the answers

Why was the classification system modified to include domains?

To address the limitations of the two-kingdom system Signup and view all the answers

Which of the following is the correct scientific name for the American black bear?

Ursus americanus Signup and view all the answers

What comprises the kingdom in the taxonomic hierarchy?

A group of related families Signup and view all the answers

What is the primary function of the condenser lens in a compound microscope?

To converge rays of light to a focal point Signup and view all the answers

Which of the following describes how resolution is affected when switching from scanning to high-power objective lenses?

Resolution increases with higher magnification Signup and view all the answers

What happens to light as it enters a denser medium from a less dense medium?

It slows down and its path changes Signup and view all the answers

Which of the following is NOT one of the main lenses in a light compound microscope?

Prism lens Signup and view all the answers

What is the refractive index of glass as compared to air?

1.52 Signup and view all the answers

Köhler illumination is primarily used to achieve:

Consistent and uniform illumination of the field Signup and view all the answers

In microscopy, increasing the refractive index of the medium used results in what effect?

Improved light transmission and resolution Signup and view all the answers

Which type of illumination technique allows for visualizing specimens against a dark background?

Dark-field illumination Signup and view all the answers

What does the Plant-Animal Dichotomy refer to?

The outdated system of separating organisms into plants and animals only Signup and view all the answers

Which nutritional mode is associated with fungi according to Whittaker's classification?

Absorptive Signup and view all the answers

What evidence does the tree of life provide about the relationship between eukaryotes and archaea?

Eukaryotes and archaea are more closely related to each other than to bacteria Signup and view all the answers

What is horizontal gene transfer?

The movement of genes from one genome to another across different species Signup and view all the answers

What should a student do if they miss a lab due to illness?

Email the instructor as soon as possible. Signup and view all the answers

What is implied by ancestor-descendant diversification?

A historical timeline measured in geological terms Signup and view all the answers

Which of the following describes horizontal gene transfer's impact on evolutionary biology?

It complicates the understanding of evolutionary relationships Signup and view all the answers

Which of the following is considered a type of biodiversity?

Species diversity Signup and view all the answers

What is the consequence of submitting a lab report that contains plagiarized content?

The case will be handled by the Code of Conduct office. Signup and view all the answers

Why was Whittaker's five-kingdom system significant for eukaryotic classification?

It created a functional-nutritional basis for dividing organisms Signup and view all the answers

What does the disparity between gene trees often indicate?

Occurrences of horizontal gene transfer among species Signup and view all the answers

What must a student bring to the first lab session?

A signed copy of the safety sheet. Signup and view all the answers

Which of the following describes genetic diversity?

Variations among the genetic resources of species. Signup and view all the answers

What happens if a student misses the quiz at the beginning of each lab?

They will receive a grade of 0 for that quiz. Signup and view all the answers

What is the primary focus of the lab reports in this course?

Documenting lab findings and analysis. Signup and view all the answers

Which of the following is not an advantage of understanding biodiversity?

Reduced reliance on technology. Signup and view all the answers

What do different varieties within the same species of rice, wheat, or maize represent?

Species diversity Signup and view all the answers

Which classification is primarily concerned with naming organisms and establishing their evolutionary relationships?

Systematics Signup and view all the answers

What is the first part of a binomial nomenclature species name called?

Genus Signup and view all the answers

What characterizes biodiversity at the ecosystem level?

Variations in microbes, plants, and animal species in an area Signup and view all the answers

What is a significant drawback of using common names for organisms?

They can be misleading and vary by region Signup and view all the answers

Which aspect of biodiversity refers to the variations observed among different ecosystems within a region?

Ecosystem diversity Signup and view all the answers

What does the term 'taxonomic classification' refer to in biology?

The classification of organisms into hierarchical groups Signup and view all the answers

What notation indicates that a species name should be italicized according to binomial nomenclature?

Only the genus name is capitalized Signup and view all the answers

Study Notes

BIOL227 Discussion 1: Introduction to the Course

This discussion introduces the BIOL227 course.
The course involves laboratory studies in biodiversity.
A wide variety of organisms from microbes to animals and plants are covered.

Lab Reports

Complete lab reports are due before leaving the lab setting.
Email instructor of illness to arrange alternative lab section, but this isn't always possible.
If a lab is missed, the remaining labs and lab quiz still contribute to the final grade.
Students are still responsible for all missed lab content in exams and quizzes.
No make-up labs are offered.
Plagiarism will not be tolerated.
Copying, paraphrasing, or translating material from any external source without citing the source is unacceptable.
Copying figures, answers, and other material from other students is prohibited.

No Electronic Devices

Laptops, netbooks, and iPads are allowed in class but not during lab.
No phones are allowed in lab or class.

Before Coming to Labs

Read the lab manual.
Watch any posted videos.
A quiz is given at the beginning of each lab (5 minutes).
Latecomers will receive a 0 grade.
Bring a signed copy of the safety sheet in the first lab.

Safety Sheet

The safety sheet is to be completed and handed in at the first lab.
Students affirm they have read and understand the Biology Department Safety Regulations.

Course Objectives

List unique features (organismal, cellular, subcellular) of a particular taxon.
Label these features (cell morphology, cell walls, food/contractile vacuoles, etc.).
Describe these features and explain their importance.
Discuss the advantages they offer to organisms and the information they provide about an organism's environment and evolutionary history.
Understand the diversity of organisms across taxonomic hierarchy levels.
Identify similarities and differences amongst taxa within a taxon category.

Biodiversity

Biodiversity represents the variety of life on Earth.
There are three main types:
Species diversity
Ecosystem diversity
Genetic diversity.
Biodiversity is crucial for life on Earth because it helps maintain stable ecosystems and provides resources.

Biodiversity: Types

Genetic diversity: Variations in the genetic makeup of organisms within a species. Examples include varieties of rice, wheat, maize, and barley.
Species diversity: Different types of species residing in specific geographic areas. This is the most basic level of biodiversity.
Ecosystem diversity: Variations in microbes, plants, and animals plus their interconnectedness through food chains and food webs. This demonstrates diversity observed in different ecosystems within a region.

Examples of Biological Diversity in the Congo River Region

Ecosystem diversity includes swamps, the Congo river, grasslands, and rainforests.
Species diversity in the tropical rainforests includes Myrianthus tree species that produce edible fruits, duikers (deer-like animals), African elephants, wild pigs, gorillas and lemur monkeys.
Genetic diversity in gorillas pertains to the alleles relating to melanin production that determine hair, skin, and eye color.

Biodiversity: Microbes, Animals, Plants

Life is organized from Domains Bacteria and Archaea (prokaryotic) to Domain Eukarya (eukaryotic) through a branching tree of life.
Domain Eukarya includes plants, animals, fungi, and protists.
Prokaryotes, in turn, are divided into domains Bacteria and Archaea

Biodiversity: Taxonomy

Taxonomy is the classification and naming of organisms based on similarities and evolutionary relationships.
The Linnaean system (Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species) categorizes organisms from broad to narrow.
Key contributors to taxonomy include Ernst Haeckel (kingdom) and Robert Whittaker (five kingdoms).

Biodiversity: Common vs Scientific Names

Common names are not always effective in classification.
Scientific names (binomial nomenclature) using genus and species, are more accurate and reliable.

Biodiversity: Binomial Nomenclature

Binomial nomenclature is a standardized two-part naming system for species.
The first part is the genus name (capitalized) and the second is the species name (lower case).
Both written together represents the species.
For example, Homo sapiens

Biodiversity: Taxonomic Classification

Taxonomists group species based on similar characteristics.
It uses a hierarchical system: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
This system is built from general (broad) to specific characteristics (narrow).
A mnemonic device for these categories is "Dumb Kings Play Chess On Fine Grain Sand".

Biodiversity: Key Contributors to Taxonomy

Early taxonomists grouped all organisms into plants or animals.
Scientists recognized difficulties with grouping fungi, bacteria, etc with either group and began the development of kingdoms.
Whittaker developed five kingdoms (fungi, plants, animals, protists, and monera).
These categories later were reclassified into three domains (Bacteria, Archaea, Eukarya) and the four kingdoms in Eukarya.

Microscopy: Learning Outcomes

Describe compound microscope parts.
Describe light bending through condenser, objectives and ocular lenses, in media such as air, water, and oil.
Explain how resolution improves from scanning to high-power objective lenses.
Practice Köhler illumination, oil immersion, and dark-field illumination.

Microscopy: Branches

Distinguish the light microscope from the electron microscope.
Determine magnification versus resolution relation.

Microscopy: Parts

Diagram and descriptions are provided for each part of a compound microscope (eyepieces, diopter adjustment ring, revolving nosepiece, specimen holder, transport lock pin, aperture iris diaphragm knob, condenser centering screws, condenser, filter holder, and field diaphragm ring).

Microscopy: Lenses

Three main lenses (condenser, objective, ocular).
The condenser lens focuses light onto the specimen to improve image clarity.

Microscopy: Refractive Index

Light changes speed and direction when moving between media with different densities (refraction).
The refractive index of a medium measures how much slower light travels compared to its velocity in a vacuum. Air=1, Glass=1.52, Oil=1.52

Microscopy: Resolution

Resolution is the ability of a lens to distinguish close objects.
Abbe's equation relates resolution to the wavelength of light, refractive index, and the angle of light entering the lens.

Microscopy: Köhler Illumination

The Köhler illumination method provides even illumination across the entire specimen field.
This method enhances image contrast and resolution by correctly centering the light cone from the condenser.

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Description

Test your knowledge on essential concepts in microscopy and taxonomy with this informative quiz. Explore key topics such as Köhler illumination, numerical aperture, and the taxonomic hierarchy. Challenge yourself and see how well you understand these fundamental principles in biology.